platform/chrome: cros_ec: Shutdown on EC Panic

platform/chrome: cros_ec: Shutdown on EC Panic

When an EC panic is reported, attempt an orderly shutdown.
Force a shutdown after a brief timeout if the orderly shutdown
fails for any reason.

Using the common hw_protection_shutdown utility function since
an EC panic has the potential to cause hw damage.

This is all best effort. EC should also force a hard reset after a
short timeout.

Signed-off-by: Rob Barnes <robbarnes@google.com>
Reviewed-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20230104011524.369764-3-robbarnes@google.com